Method of converting polyhedral oligomeric silsesquioxane (POSS) type T8 into type 10

ABSTRACT

The conversion method of T 8  type Polyhedral Oligomeric Silsesquioxanes (POSS) into T 10  type compounds, includes treating octasilsesquioxane of the general formula (RSiO 1.5 ) 8  (wherein R is hydride, ethyl, vinyl, 3-chloropropyl, 3-hydroxypropyl, phenyl, octyl, 3-decanaminepropyl, 3-benzamideamidepropyl group and 3-aminepropyl hydrochloride group) with at least 10-fold excess of organic acid giving decasilsesquioxane (RSiO 1.5 ) 10 . The reaction is conducted in air.

RELATED U.S. APPLICATIONS

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STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

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REFERENCE TO MICROFICHE APPENDIX

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BACKGROUND OF THE INVENTION

1. Field of the Invention

The subject of the invention is the conversion method of T₈ type Polyhedral Oligomeric Silsesquioxanes (POSS) to T₁₀ type compounds using acidic catalyst.

2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 37 CFR 1.98.

Most Polyhedral (multiwalled) Oligomeric Silsesquioxanes (POSS) are specific example of silsesquioxanes (SQ) which are described by the specific formula (RSiO_(1,5))_(n), wherein R symbol indicate hydrogen atom, alkyl group, aryl group, halogen, alkenyl group and derivatives thereof, usually n have a value: 6, 8, 10, 12. SQ is most frequently prepared by hydrolysis and subsequent condensation of trifunctional silanes in slightly elevated or room temperature in and using basic and acidic catalyst. As a precursor for SQ synthesis specific silanes RSiX₃ (X=Cl, OR, OAc, NH₂ and other) are used which are easy to hydrolyse giving silanol groups and are further subjected to polycondensation. Hydrolysis speed depends on the type of substituent on silica atom which are not hydrolysed (bigger substituent, lower speed) and type of X function group. Besides, temperature, monomer concentration, amount of water added, type of solvent and catalyst are also influencing the efficiency. Polycondensation performed in such manner gives various structures of silsesquioxanes as presented on FIG. 1.

Apart from SQ presented above, POSS in small amounts are also generated during hydrolytic polycondensation reaction. Cage-formed and constructed from complete multiple one-and-half silicate RSiO_(1,5) units SQ are also included. POSS are signed with T_(n) symbol, wherein usually n have a 6, 8, 10, 12 value and indicate amount of silica atoms present in the corner of polyhedron.

Polyhedral oligomeric silsesquioxanes are prepared in general from organic trichloro- or trialkoxysilanes in hydrolytic polycondensation process described above. Most commonly used catalyst of this reaction are non-organic acid such as e.g. HCl, H₂SO₄ or bases (organic amines, metal hydroxides). It is necessary to use moderate amounts of water (most preferably in molar H₂O/RSiX₃ ratio=1:1) in order to maintain heterofunctional condensation instead of competitive homocondensation of silanols.

Typical POSS structures are presented on FIG. 2.

Most commonly found are type T₈ compounds due to presence of four interconnected Si₄O₄ with high rings stability which compose core of the cage. Generation of less thermodynamically unstable POSS such as T₁₀ or T₁₂ is a result of spontaneous conversion of T₈ type POSS. In general, they are produced with low efficiency as a by-products in reaction of POSS arms modification. Such T₈ cage modification into the bigger one was published by several research groups [(a) Y. Kawakami, K. Yamaguchi, T. Yokozawa, T. Serizawa, M. Hasegawa, Y. Kabe, Chem. Lett. 2007, 36, 792; (b) A. R. Bassindale, Z. Liu, I. A. Mackinnon, P. G. Taylor, Y. Yang, M. E. 100 Light, P. N. Horton, M. B. Hursthouse, Dalton Trans. 2003, 2945. (c) V. Ervithayasuporn, X. Wang, Y. Kawakami, Chem. Commun. 2009, 5130].

Nevertheless, these compounds most commonly were not isolated in a pure form. It is directly connected to the similarity in solubility for compounds of T₈, T₁₀, T₁₂ type and higher. Separation of POSS is particularly difficult when compounds, e.g. T₁₀ and T₁₂, exhibit similar physico-chemical properties.

Kawakami et al. described generation of POSS T₈, T₁₀ and T₁₂ during hydrolysis of 4-substituted phenyltriethoxysilan in presence of TBAF (tetrabutylammonium fluoride). Separation of POSS with different cage size is conducted by crystallization using different type of solvent solutions e.g. acetonitrile/THF (v/v, 1:1), pure hexane or ethanol/hexane mixtures (v/v, 1:4). Known ways to obtain T₁₀ and T₁₂ cages are presented in Table 1 based on publication: Lickiss, P. D.; Rataboul, F. Fully Condensed Polyhedral Oligosilsesquioxanes (POSS): From Synthesis to Application. Adv. Organomet. Chem. 2008, 57, 1-116.

TABLE 1 Examples of reaction conditions to obtain different T₈ or T₁₂ type silsesquioxanes. The value of the chemical Cage Type of R Starting compound Efficiency shift ²⁹Si size substituent and reaction conditions [%] NMR T₁₀ —H HSiCl₃ + c-C₆H₁₂/PhMe + 3.6 −86.25 H₂SO₄ —Cp CpSiCl₃ + H₂O, 67 −71.50 THF + (NH₄)₂CO₃, 7 days —CH═CH₂ [CH₂═CHSi(OEt)₂]₂O + 26 −81.48 H₂O, TBF, THF/CH₂Cl₂, 2 days —C₆H₅ PhSiCl₃ + H₂O, toluene, — — KOH, 9 h, subsequently re- crystallization from benzene/ n-hexane mixture T₁₂ —H HSiCl₃ + H₂O, H₂SO₄, 3.5 −85.78, cyclohexane/toluene, 6 h −87.76 —CH═CH₂ [CH₂═CHSi(OEt)₂]₂O + H₂O, 15 −81.34, TBF, THF/CH₂Cl₂, 2 days −83.35 —C₆H₅ PhSiCl₃ + H₂O, KOH, THF, — — reflux, 3 days

Besides above methods there is a method know in the literature for obtaining T₁₀ type cages by conversion of SQ using fluoride ions. Rikowski et al. found that T₁₀ and T₁₂ POSSs are generated as a result of T₈ cage conversion using NaF and 18-crown-6 as a catalyst. This conversion has given following efficiencies: 28% T₈, 61% T₁₀ and 11% T₁₂.

Surprisingly, it has been discovered that usage of organic acid in form of triflic acid as a catalyst in conversion process of polyhedral oligomeric silsesquioxane constructed as a closed cage consisting of eight RSiO_(1.5) units (T₈ cage; [RSiO_(1.5)]₈) into the cage made of ten RSiO_(1.5) units (T₁₀ cage; [RSiO_(1.5)]₈) enabled obtaining high efficiency of the process and isolation of crude reaction products in pure form.

SUMMARY OF THE INVENTION

The essence of the invention is the conversion method of T₈ type Polyhedral Oligomeric Silsesquioxanes (POSS) into T₁₀ type compounds, characterised in that octasilsesquioxane of the general formula (RSiO_(1.5))₈ (wherein R is hydride, ethyl, vinyl, 3-chloropropyl, 3-hydroxypropyl, phenyl, octyl, 3-decanaminepropyl, 3-benzamideamidepropyl group and 3-aminepropyl hydrochloride group) was treated with at least 10-fold excess of organic acid giving decasilsesquioxane (RSiO_(1.5))₁₀, wherein reaction is conducted in air.

Preferably, an organic acid is trifluoromethanesulfonic acid (CF₃SO₃H).

Preferably, T₈ type POSS is initially dissolved in polar solvent, preferably dimethylsulfoxide (DMSO), methanol, acetone, N,N-dimethylformamide (DMF), acetonitrile, hexamethylphosphoramide (HMPA), N-methylformamide.

Preferably, type T₈ POSS conversion reaction into T₁₀ type POSS is conducted for at least 2 h in temperature of 40° C.

Reaction was conducted in DMSO solution in temperature of 40° C. End product was isolated through extraction from solid postreaction mixture using acetone.

Identification of compounds was performed using elemental analysis, infra-red spectroscopy, NMR spectroscopy (¹H, ¹³O and ²⁹Si) and mass spectrometry.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention was described in more details in exemplary embodiments and in the figures.

FIG. 1 shows a schematic view of exemplary SQ structures.

FIG. 2 shows a schematic view exemplary POSS structures.

FIG. 3 shows a schematic view of a mechanism of conducted reaction.

FIG. 4 shows a schematic view of illustrations of obtained T₁₀ type compounds.

DETAILED DESCRIPTION OF THE DRAWINGS Example 1

Triflic acid (12 eq, 1.022 mmol, 0.154 g, 0.0905 mL) was added dropwise to the solution of oct(3-aminepropyl)silsesquioxane hydrochloride (0.100 g, 0.0852 mmol) in DMSO (5 mL). Obtained solution was mixed for 2 hours in temperature of 40° C. under oxygen and was subsequently chilled to room temperature, solvent was purged with nitrogen stream. Obtained yellow sediment was rinsed with acetone (3×15 mL). Filtered and solvent was subsequently evaporated obtaining white powder which is deca(3-aminepropyl)silsesquioxane triflic salt with 44% efficiency (0.078 g).

Elemental analysis calculated (%) for C₄₀H₈₈F₃₀N₁₀O₄₅S₁₀Si₁₀ (2600.62): C, 18.48; H, 3.41; N, 5.39; S, 12.31. found: C, 18.55; H, 3.31; N, 5.32; S, 12.42.

FT-IR (cm⁻¹, KBr pellets): ν_(N—H)=3041 (s), δ_(NH3)=1615 (m), ν_(C—N)=1507 (m), ν_(C—F)=1267 (s), ν_(Si—C)=1226 (m), ν_(Si—O—Si)=1138 (s), ν_(SO3)=1031 (s), ν_(S—N)=640 (s).

¹H NMR (500 MHz, DMSO-d₆, 300 K): δ=7.52 (s, 30H, NH₃ ⁺), 2.73 (t, ³J_(HH)=7.2 Hz, 20H, CH₂NH₃ ⁺), 1.49 (m, 20H, SiCH₂CH₂CH₂NH₃ ⁺), 0.59 (t, ³J_(HH)=8.6 Hz, 20H, SiCH₂)

¹³C{¹H} NMR (126 MHz, DMSO-d₆, 300 K): δ=122.5 (q, ¹J_(C—F)=317 Hz, CF₃SO₃ ⁻), 41.1 (s, SiCH₂CH₂CH₂NH₃ ⁺), 20.6 (s, SiCH₂CH₂CH₂NH₃ ⁺), 8.2 (s, SiCH₂CH₂CH₂NH₃ ⁺).

HR-MS (ESI+, TOF, MeOH), m/z: 567.7398 [M+3H-6CF₃SO₃H]³⁺ (theoret. 567.7367), 517.7479 [M+3H-7 CF₃SO₃H]₃₊ (theoret. 517.7504), 467.7697 [M+3H-8 CF₃SO₃H]³⁺ (theoret. 467.7638), 426.1133 [M+4H-6 CF₃SO₃H]₄₊ (theoret. 426.0545), 417.7837 [M+3H-9CF₃SO₃H]³⁺ (theoret. 417.7771), 401.4678 [M+5H-4CF₃SO₃H]⁵⁺ (theoret. 401.2029), 388.5721 [M+5H-7CF₃SO₃H]⁵⁺ (theoret. 388.5646), 371.7947 [M+5H-5CF₃SO₃H]⁵⁺ (theoret. 371.0371), 367.8035 [M+5H-10CF₃SO₃H]⁵⁺ (theoret. 367.7905), 351.0974 [M+4H-8CF₃SO₃H]⁴⁺ (theoret. 351.0746), 313.5899 [M+4H-9CF₃SO₃H]⁴⁺ (theoret. 313.5847), 311.0972 [M+5H-7CF₃SO₃H]⁵⁺ (theoret. 311.0531), 281.0678 [M+5H-8CF₃SO₃H]⁵⁺ (theoret. 281.0612), 276.0995 [M+4H-10CF₃SO₃H]⁴⁺ (theoret. 276.0947), 250.8448 [M+5H-9CF₃SO₃H]⁵⁺ (theoret. 250.8676).

²⁹Si{¹H} NMR (59.6 MHz, DMSO-d6, 20° C.): δ=−68.48 (s, T³).

Example 2

Deca(hydrydo)silsesquioxane was obtained in analogy to example 1 using octa(hydrydo)silsesquioxane as a starting compound (0.036 g, 0.0852 mmol), reaction was conducted in acetone (5 mL). White powder was obtained with 40% efficiency (0.018 g).

Elemental analysis calculated (%) for H₁₀O₁₅Si₁₀ (530.97): C, 0.00; H, 1.90; N, 0.00. found: C, 0.00; H, 1.92; N, 0.00.

HR-MS (ESI+, TOF, MeOH), m/z: 530.7781 [M+H]⁺ (theoret. 530.7785).

Example 3

Deca(ethyl)silsesquioxane was obtained in analogy to example 1 using octa(ethyl)silsesquioxane as a starting compound (0.055 g, 0.0852 mmol), reaction was conducted in DMF (5 mL). White powder was obtained with 39% efficiency (0.043 g).

Elemental analysis calculated (%) for C₂₀H₅₀O₁₅Si₁₀ (811.50) C, 29.60; H, 6.21; N, 0.00. found: C, 29.66; H, 6.28; N, 0.00.

HR-MS (ESI+, TOF, CHCl₃), m/z: 811.0922 [M+H]⁺ (theoret. 811.0915).

Example 4

Deca(vinyl)silsesquioxane was obtained in analogy to example 1 using octa(vinyl)silsesquioxane as a starting compound (0.054 g, 0.0852 mmol), reaction was conducted in N-methylformamide (10 mL). White powder was obtained with 45% efficiency (0.030 g).

Elemental analysis calculated (%) for C₂₀H₃₀O₁₅Si₁₀ (791.35) C, 30.36; H, 3.82; N, 0.00. found: C, 30.31; H, 3.85; N, 0.00.

HR-MS (ESI+, TOF, THF), m/z: 790.9348 [M+H]⁺ (theoret. 790.9350).

Example 5

Deca(3-chloropropyl)silsesquioxane was obtained in analogy to example 1 using octa(3-chloropropyl)silsesquioxane as a starting compound (0.088 g, 0.0852 mmol), reaction was conducted in methanol (10 mL). White powder was obtained with 48% efficiency (0.053 g).

Elemental analysis calculated (%) for C₃₀H₆₀Cl₁₀O₁₅Si₁₀ (1296.27) C, 27.80; H, 4.67; N, 0.00; Cl, 27.35. found: C, 27.84; H, 4.63; N, 0.00; Cl, 27.31.

HR-MS (ESI+, TOF, THF), m/z: 1290.8578 [M+H]⁺ (theoret. 1290.8583).

Example 6

Deca(3-hydroxypropyl)silsesquioxane was obtained in analogy to example 1 using octa(3-hydroxypropyl)silsesquioxane as a starting compound (0.113 g, 0.0852 mmol), reaction was conducted in DMSO (5 mL). White powder was obtained with 53% efficiency (0.050 g).

Elemental analysis calculated (%) for C₃₀H₇₀O₂₅Si₁₀ (1111.77) C, 32.41; H, 6.35; N, 0.00. found: C, 32.48; H, 6.28; N, 0.00.

HR-MS (ESI+, TOF, CHCl₃), m/z: 1111.1968 [M+H]⁺ (theoret. 1111.1972).

Example 7

Deca(phenyl)silsesquioxane was obtained in analogy to example 1 using octa(phenyl)silsesquioxane as a starting compound (0.088 g, 0.0852 mmol), reaction was conducted in HPMA (10 mL). White powder was obtained with 44% efficiency (0.048 g).

Elemental analysis calculated (%) for C₆₀H₅₀O₁₅Si₁₀ (1291.94) C, 55.78; H, 3.90; N, 0.00. found: C, 55.75; H, 3.95; N, 0.00.

HR-MS (ESI+, TOF, CHCl₃), m/z: 1291.0908 [M+H]⁺ (theoret. 1291.0915).

Example 8

Deca(octyl)silsesquioxane was obtained in analogy to example 1 using octa(ethyl)silsesquioxane as a starting compound (0.113 g, 0.0852 mmol), reaction was conducted in DMF (5 mL). White powder was obtained with 51% efficiency (0.072 g).

Elemental analysis calculated (%) for C₈₀H₁₇₀O₁₅Si₁₀ (1653.12) C, 58.13; H, 10.37; N, 0.00. found: C, 58.10; H, 10.31; N, 0.00.

HR-MS (ESI+, TOF, CHCl₃), m/z: 1652.0305 [M+H]⁺ (theoret. 1652.0305).

Example 9

Deca(3-decanamidepropyl)silsesquioxane was obtained in analogy to example 1 using octa(3-decanamidepropyl)silsesquioxane as a starting compound (0.180 g, 0.0852 mmol), reaction was conducted in acetonitrile (5 mL). White powder was obtained with 43% efficiency (0.097 g).

Elemental analysis calculated (%) for C₁₃₀H₂₆₀N₁₀O₂₅Si₁₀ (2644.45) C, 59.05; H, 9.91; N, 5.30. found: C, 59.01; H, 9.93; N, 5.29.

FT-IR (cm⁻¹, KBr pellets): ν_(N—H)=3278 (s), ν_(C—H)=2931 (m), ν_(C—H)=2871 (m), ν_(C═O)=1636 (5), δ_(NH)=1558 (s), 1457(w), ν_(C—N)=1383 (m), (w), 1272 (w), V_(ring-asym. Si—O—Si)=1122 (5), δ_(O—Si—O)=698 (w), δ_(O—Si—O)=472 (w).

HR-MS (ESI+, TOF, CHCl₃), m/z: 1321.8756 [M+2H]²⁺ (theoret. 1321.8610), 881.5648 [M+3H]³⁺ (theoret. 881.5764).

¹H NMR (500 MHz, CDCl₃, 300 K): δ=3.15 (t, ³J_(HH)=7.0 Hz, 20H, CH₂NH), 2.51 (t, ³J_(HH)=7.4 Hz, 20H, C(O)CH₂), 1.52 (br, 40H, SiCH₂CH₂CH₂ and C(O)CH₂ CH₂, 1.20-1.25 (br, 120H, —CH₂—), 0.82 (t, ³J_(HH)=7.0 Hz, 30H, CH₃), 0.56 (t, ³J_(HH)=8.4 Hz, 20H, SiCH₂).

¹³C{¹H} NMR (126 MHz, CDCl₃, 300 K): δ=169.3 (s, C═O), 42.2 (s, SiCH₂CH₂CH₂NH), 31.9 (s, C(O)CH₂), 30.7, 29.5, 29.4, 29.3, 29.3, 29.2, (5, —CH₂—), 22.9 (s, SiCH₂CH₂CH₂NH), 22.7 (s, C(O)CH₂CH₂), 14.1 (s, CH₃), 9.2 (s, SiCH₂CH₂CH₂NH).

²⁹Si{¹H} NMR (59.6 MHz, 59.6 MHz, CDCl₃, 300 K): δ=−68.54 (5, T³).

Example 10

Deca(3-benzamideamidepropyl)silsesquioxane was obtained in analogy to example 1 using octa(3-benzamideamidepropyl)silsesquioxane as a starting compound (0.146 g, 0.0852 mmol), reaction was conducted in DMF (5 mL). White powder was obtained with 60% efficiency (0.110 g).

Elemental analysis calculated (%) for C₁₀₀H₁₂₀N₁₀O₂₅Si₁₀ (1653.12) C, 56.05; H, 5.64; N, 6.54. found: C, 56.01; H, 5.68; N, 6.57.

HR-MS (ESI+, TOF, CHCl₃), m/z: 2141.6187 [M+H]⁺ (theoret. 2141.6192).

POSS application possibilities are vast and depend on substituents attached to the POSS cage corners. Variety of POSS derivatives are known with substituents such as hydrogen atoms or such a groups as: alkoxide, amine, acryl, metacryl, halogen, nitrile, phenyl, fluoralkyl, alkenyl, thiol and other.

POSS compounds gives higher mechanical and thermal durability to the materials which they modify. Potential and real applications include e.g. resistors to obtain new materials for lithography, high-temperature greases, materials with low dielectric constant, pigment dispersants. POSS compounds can be used in biomaterial chemistry as a systems for drug delivery, antimicrobial coatings, component of dental nanocomposites. POSS can be used in electronics and optoelectronics (in LED diodes), in separation membranes for oil/water systems and in materials for space industry. POSS are also used in cosmetics, printing inks and to modify material surface in order to obtain hydrophobic, self-cleaning properties and higher wear resistance. 

We claim:
 1. A method of converting T₈ type Polyhedral Oligomeric Silsesquioxanes (POSS) into T₁₀ type compounds, comprising the steps of: treating octasilsesquioxane of general formula (RSiO_(1.5))₈ (wherein R is hydride, ethyl, vinyl, 3-chloropropyl, 3-hydroxypropyl, phenyl, octyl, 3-decanaminepropyl, 3-benzamideamidepropyl group and 3-aminepropyl hydrochloride group) with at least 10-fold excess of organic acid giving decasilsesquioxane (RSiO_(1.5))₁₀; and conducting the reaction in air.
 2. Method according to claim 1, wherein said organic acid is comprised of trifluoromethanesulfonic acid (CF₃SO₃H).
 3. Method according to claim 1, said method further comprising: dissolving said octasilsesquioxane in polar solvent, wherein said polar solvent is selected from one of a group consisting of dimethylsulfoxide (DMSO), methanol, acetone, N,N-dimethylformamide (DMF), acetonitrile, hexamethylfosforamide (HMPA), and N-methylformamide.
 4. Method according to claim 1, wherein the step of conducting said reaction is at least two hour at a temperature of 40° C. 